MALDI-TOF spectrometry has not been used for urinary exosome analysis. We used it for determining UC
biomarkers. From 2012 to 2015, we enrolled 129 consecutive patients with UC and 62 participants without UC. Exosomes from their urine were isolated, and analyzed through MALDI-TOF spectrometry. Immunohistochemical (IHC) analysis of another 122 UC and 26 non-UC tissues was conducted to verify the discovered
biomarkers. Two peaks at m/z 5593 (fragmented
peptide of
alpha-1-antitrypsin; sensitivity, 50.4%; specificity, 96.9%) and m/z 5947 (fragmented
peptide of
histone H2B1K sensitivity, 62.0%; specificity, 92.3%) were identified as UC diagnosis exosome
biomarkers. UC patients with detectable
histone H2B1K showed 2.29- and 3.11-fold increased risks of recurrence and progression, respectively, compared with those with nondetectable
histone H2B1K. Verification results of IHC staining revealed significantly higher expression of
alpha 1-antitrypsin (p = 0.038) and H2B1K (p = 0.005) in UC tissues than in normal tissues. The expression of
alpha 1-antitrypsin and H2B1K in UC tissues was significantly correlated with UC grades (p < 0.05). Urinary exosome
proteins alpha 1-antitrypsin and
histone H2B1K, which are identified through MALDI-TOF analysis, could facilitate rapid diagnosis and prognosis of UC.